Influence of grain size on the photo-stability of perovskite solar cells

Organometallic perovskite solar cells have recently attracted huge attention as one of the most promising photovoltaic technologies. Despite higher efficiency achieved in recent years, the instability of perovskite solar cells remains as the biggest problem to be solved. Recently, researchers have developed several encapsulation techniques to enhance the device stability against moisture, but the stability of the device under light soaking did not receive that much attention. Previously, we had studied the device physics behind photo-induced degradation of the perovskite solar cells, and we found that the performance degradation during light exposure is attributed to the generation and migration of mobile ions. In this paper, we investigated the effect of the grain size on the photo-stability and mobile ion generation in perovskite solar cells. We found that with larger perovskite film grain size, the ion generation rate decreased significantly under light exposure, which leads to less performance degradation. This result was further confirmed by our ion density measurement using transient ionic current.

Automated summary

Organometallic perovskite solar cells, as one of the most promising photovoltaic technologies, have achieved higher efficiency but still face stability issues. Research shows that with larger perovskite film grain size, the ion generation rate decreases significantly under light exposure, resulting in less performance degradation.